II), Bismuth Research Articles

FREQUENCY TRANSDUCER OF MAGNETIC FIELD INDUCTION BASED ON HETEROMETALLIC COMPLEX COMPOUND

The possibilities of using nanocomposite material µ-methoxo (copper (II), bismuth (III)) acetylacetonate (I), the following composition: Cu3Bi(AA)4(OCH3)5, де HAA = H3C–C(O)–CH2–C(O)–CH3, as a magnetoresistive sensitive element, in a frequency transducer of a magnetic field. In order to create a suitable heterometallic complex compound, a method for its synthesis was developed. The structure, composition and physicochemical properties of the synthesized nanocomposite material were confirmed on the basis of elemental, X-ray phase analyzes, magnetochemical, IR spectroscopic and thermogravimetric studies. According to research, the density of the corresponding material 𝜌=5,659⋅103 g/m3, the mass of one molecule 𝑚0 = 157,837⋅10−26 kg, the number of valence electrons 𝑁=1450,715⋅1019, which made it possible to calculate the concentration of charge carriers at a temperature of 323 K: 𝑛=82.1⋅1028 m−3. The study of the electrical properties of µ-methoxo (copper (II), bismuth (III)) acetylacetonate in compressed form in the temperature range 323 - 393 K showed that with increasing temperature, its resistivity drops sharply from 8·107 to 70 Ohm·cm, which is typical for semiconductor materials. Based on these data, the band gap 𝛥𝛦 = 2.18 eV was determined. Calculations have shown that this material is a semiconductor, with current carriers of both signs. The dependence of the concentration of charge carriers on the temperature is obtained. The model of the frequency transducer, on the basis of the autogenerator from bipolar to field-effect transistors is considered. Simulation of this scheme was performed in the program LTspice XVIII. Based on this model, the I – V characteristics of this transducer, the dependence of the current, voltage and frequency of the output signal when changing the resistance of the magnetically sensitive resistor. The graph of dependence of frequency of an output signal on induction of a magnetic field on the basis of which sensitivity of the given transducer is defined is received

Кобальт(II) иондарын су ерiтiндiлерiнен органикалық реагенттер балқымасымен экстракциялық алу және аналитикалық анықтау әдiсiн жасау

Cobalt is a relatively rare metal, and its rich deposits are now almost exhausted. The main sources of industrial production of metallic cobalt are copper-nickel ores containing cobalt as an impurity. The processing of these ores is very complex and involves pyro- and hydrometallurgical methods depending on the composition of the ore. The result is a solution of cobalt and nickel chlorides containing impurities of copper(II), lead(II), bismuth(III) ions. Extraction is increasingly used to purify cobalt from associated impurities. Extraction methods are widely used in hydrometallurgy, the nuclear materials industry, the technology of rare metals and the production of highly pure substances, as well as in analytical chemistry. However, despite this they have a number of drawbacks the main one is the use of fire hazardous and toxic organic solvents; therefore, the principles of eliminating toxic components from the process are becoming more common. The physicochemical basis of the extraction of cobalt (II) ions was studied by a stearic acid melt.The possibilities of practical application are considered of research results. Solid extracts of cobalt(II) were obtained with low-melting organic extractants. They meet all the requirements of standard samples: they differ in homogeneity of distribution, in similarity of composition with the analyzed samples and they can be used for several years.

Selective liquid-liquid extraction of antimony(III) from hydrochloric acid media by N-n-octylaniline in xylene

N-n-Octylaniline in xylene was used for the extraction separation of antimony( III) from hydrochloric acid media. Antimony(III) was extracted quantitatively with 10 mL4%N-n-octylaniline in xylene. It was stripped from the organic phase with 0.5 M ammonia and estimated photometrically by the iodide method. The effect of metal ion, acid, reagent concentration and various foreign ions was investigated. The method affords binary and ternary separation of antimony(III) from tellurium(IV), selenium( IV), lead(II) bismuth(III), tin(IV), germanium(IV), copper(II), gold(III), iron(III) and zinc(II). The method is applicable for the analysis of synthetic mixtures alloys and semiconductor thin films. It is fast, accurate and precise.

Synthesis and molecular structure of the dihydrobis(thioxotriazolinyl)borato complexes of zinc(II), bismuth(III), and nickel(II). M...H-B interaction studied by Ab initio calculations.

Reacting the heterocycle 5-thioxo-1,4-dihydro-4-ethyl-3-methyl-1,2,4-triazole (thioxotriazoline) with sodium tetrahydroborate in the molar ratio of approximately 2:1 at 130 degrees C provides the new ligand dihydrobis(thioxotriazolinyl)borato, [Bt(Et,Me)](-), as its sodium salt. The neutral complexes of this anionic ligand with zinc(II), bismuth(III), and nickel(II) have been synthesized and characterized by X-ray crystallography. In every complex, the ligand is coordinated to the metal in the S(2) mode, generating eight-membered chelate rings. The bismuth and nickel complexes exhibit two M.H-B interactions responsible for the dodecahedral and octahedral geometries, respectively. For the zinc complex, the trigonal-bipyramidal coordination is achieved with an apical Zn.H-B interaction. The crystal structures for the three complexes are described, and ab initio calculations on Bi(III), Ni(II), and Zn(II) compounds have been performed in order to assess the nature of the M.H-B interaction and its role for the definition of the molecular geometries.

Metal Sulfide Synthesis by Self-Propagating Combustion of Sulfur-Containing Complexes

Coordination compounds of thiourea with cadmium(II), zinc(II), bismuth(III), and indium(III) nitrates were synthesized. The self-sustained combustion of these complexes, as well as that of thiosemicarbazide coordination compounds of nickel(II), cobalt(II), iron(II), copper(II), lead(II), and zinc(II) nitrates, was studied in an inert atmosphere. All these compounds burn to yield metal sulfides. The particle size and morphology of the product depend on the pressure at which the process is carried out. For cadmium(II) and zinc(II) sulfides, which are capable of subliming at the combustion temperatures of their precursors, these parameters can be varied in wide ranges.

Thermal expansion of francisite, [Cu 3 BiO 2 ](SeO 3 ) 2 Cl, and its interpretation based on oxocentered copper-bismuth tetrahedra

The thermal expansion of francisite, [Cu3BiO2](SeO3)2Cl, a rare copper(II)-bismuth(III) oxide chloride selenite, was studied by high-temperature X-ray powder diffraction over the temperature range 293–773 K. The mineral is stable up to 748 K at which temperature it decomposes to [Bi2O2]Se, CuO and, probably, [BiO][CuSe]. The thermal expansion has an anisotropic character (αa = 9.0, αb = 4.7, αc = 17.0 · 10−6 K−1), which is determined by the distribution of the bonds between additional oxygen atoms (aO) and metal atoms (A). These bonds form two-dimensional systems in which each aO atom is tetrahedrally coordinated by one Bi and three Cu atoms. Thus the structure can be described in terms of oxocentered metal atom tetrahedra consisting of [aO2Cu3Bi] layers of (aOCu3Bi) tetrahedra, (SeO3) groups and Cl anions. This description gives the most reasonable viewpoint to explain the anisotropic thermal expansion character of francisite.

Adsorption of Thallium(I), Lead(II), Copper(II), Bismuth(III) and Chromium(III) by Electrolytic Manganese Dioxide

The adsorption of thallium(I), lead(II), copper(II), bismuth(III) and chromium(III) by electrolytic manganese dioxide (EMD) has been followed between pH 2–5 [except for bismuth(III)), where a single pH of 1.5 was employed] at 20°C and an ionic strength of 0.5, employing a wide range of initial metal ion concentrations from 5 × 10−5 mol/dm3 to 5 × 10−2 mol/dm3. The adsorption isotherms all fitted a simple Langmuir adsorption equation quite well. The amount of metal ion adsorbed increased with pH for lead and copper ion. However, for both thallium and chromium, a significant drop in adsorption between pH 3 and 4 was observed, associated with the dominant presence of lower-charged hydroxy species at higher pH values. At pH 4, adsorption was in the order PbII > CuII > TII >> CrIII, whereas at pH ≤ 2 the order was BiIII ≤ PbII > TlI > CrIII > CuII. In the low pH range, which is largely free of hydrolysis species, the adsorption of the isoelectronic bismuth, lead and thallium series appears to be dominated by charge, and charge appears a dominant factor with the transition metal pair also. The adsorption of lead (at pH 4 and 5) and bismuth (at pH 1.5) to samples of EMD subjected to prolonged heat treatment at 110, 400 and 650°C were also examined. Samples dried at 110°C mainly lost only surface water, and showed adsorption characteristics similar to untreated samples. Samples heated at 400°C lost all their combined water but still showed significant adsorption, whereas samples heated at 600°C were converted to Mn2O3, and showed very small though measurable metal ion adsorption.

Spectrophotometric and derivative spectrophotometric determination of nickel with hydroxynaphthol blue

The reaction of nickel(II) cation with hydroxynaphthol blue (HNB) in aqueous media at pH 5.2–6.0 results in a red complex that is stable for at least 2h. Beer's Law is obeyed up to 3.2 μg/ml of nickel(II) with an apparent molar absorptivity of 1.38 × 104l/mol/cm at 563 nm. This paper proposes procedures for nickel determination by ordinary and first-derivative spectrophotometry. The results demonstrate that the linear dynamic range is 0.08–3.20 μg/ml with a limit of detection of 23 ng/ml for ordinary spectrophotometry, compared with 21–800 ng/ml and 6 ng/ml, respectively, for first-derivative spectrophotometry. Calcium(II), magnesium(II), barium(II), strontium(II), cadmium(II), lead(II), manganese(II), bismuth(III) and molybdenum(VI) ions do not interfere for at least 100∶1 mass ratios. The main interferents are cobalt(II), titanium(IV), aluminium(III), mercury(II) and copper(II). The interferences of titanium(IV), aluminium(III), zirconium(IV) and iron(III) can be masked by fluoride and mercury(II) and copper(II) with thiosulfate or thiourea. The derivative method is applied to nickel determination in standard brasses and the results demonstrate that there is no significant difference between the results and certified values at the 95% confidence level.

Separation of Cadmium Salicylate by Solvent Extraction Using Tris(2-ethylhexyl) Phosphate

Abstract Tris(2-ethylhexyl) phosphate (T2EHP) is used for the extraction of cadmium salicylate. The experimental conditions are established and the probable extractable species is ascertained by log D–log C plots. Microgram amounts of cadmium are determined in the Tris(2-ethylhexyl) phosphate phase with 1-(2-pyridylazo)-2-naphthol as the chromogenic agent. The proposed method is used for the separation of cadmium(II) from zinc(II), mercury(II), lead(II), bismuth(III), antimony(III), and thallium(III) and used for the estimation of cadmium in industrial waste water, kidney stone, cigarettes, and alloy samples.

Separation and determination of trace amounts of vanadium(V), chromium(III) and iron(III) with 2-(2-thienylazo)-5-diethylaminophenol chelates by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method for the separation and the determination of vanadium(V), chromium(III) and iron(III) with 2-(2-thienylazo)-5-diethylaminophenol chelates on a C 18-bonded stationary phase by using methanol-tetrahydrofuran- (20:15:65, v/v/v) containing 0.05 M lithium sulphate and 0.04 M acetate buffer (pH 5.5) as mobile phase and with spectrophotometric detection at 570 nm was developed. The method has high sensitivity, the detection limits being 0.5 ppb for vanadium(V), 2 ppb for chromium(III) and 1 ppb for iron(III). Under the optimum conditions, most other metal ions did not interfere, e.g., up to 1000 μg of magnesium(III), cadmum(II), zinc(II), lead(II), manganese(II), calcium(II), barium(II), tin(II, IV) and tungsten (VI), 400 μg of thorium(IV), 200 μg of iron(II), bismuth(III), zirconium(IV), 150 μg of gallium(III) and 120 μg of lanthanum(III) in the determination of 2.5 μg of iron(III) and chromium(III) and 1 μg of vanadium(V). The method can be applied to the simultaneous determination of trace amounts of vanadium(V), chromium(III) and iron(III) in water, tea leaves and rice samples.

Voltammetric determination of mercury(II) at a carbon paste electrode in aqueous solutions containing tetraphenylborate ion

The determination of mercury(II) ions can be achieved by monitoring the decrease in the oxidation peak of the tetraphenylborate ion in the presence of this metal ion at a carbon paste electrode. The reaction between mercury(II) and the tetraphenylborate ion results in the formation of diphenylmercury, thus providing the method with good selectivity over other metal ions. Using anodic stripping voltammetry in a neutral electrolyte, a linear dependence of the decrease of peak height was observed on increasing the mercury(II) concentration in the range 1 × 10 −6–8 × 10 −9 M mercury(II). Zinc(II), cadmium(II), lead(II), nickel(II), cobalt(II), tin(II), potassium(I) and ammonium(I) ions did not interfere at a 1000-fold concentration excess. Iron(III) and chromium(III) did not interfere at a 250-fold and 50-fold concentration excess, respectively. Following masking procedures, copper(II), bismuth(III) and silver(I) did not interfere at a 100-fold concentration excess. The method can be used to determine the concentration of mercury(II) in natural waters contaminated by this metal.

Electrochemically generated copper(II), tin(II), bismuth(III) and zinc(II) complexes in dichloromethane containing tetrabutylammonium perchlorate, tetrafluoroborate or hexafluorophosphate as the electrolyte

Oxidation of M(amalgam)(M = Cu, Sn, Bi or Zn) electrodes under direct current and differential pulse polarographic or cyclic voltammetric conditions in dichloromethane containing 0.2 mol dm–3[NBu4][PF6], [NBu4][BF4] or [NBu4][CIO4] as an electrolyte generates weakly solvated and therefore very reactive Cu2+, Sn2+, Bi3+ and Zn2+ cations. Since the kinetics of nucleation and precipitation of the usually formed insoluble salts is slow on the voltammetric time-scale, data on the formation of complexes with the electrolyte anions can be obtained. A general order of stability, [PF6]–[BF4]– < [ClO4]–, was found for all metals. However, since the Zn (amalgam)→ Zn2+ oxidation process is completely irreversible, quantitative stability constant data on the complexes formed with Zn2+ could not be obtained. From these and other data it is concluded that [PF6]– generally seems to represent an example of a very weak ligand for metal cations in relatively non-co-ordinating solvent such as dichloromethane. Mechanical transfer of small amounts of metallic Sn and Pb onto a platinum electrode and use of the method of abrasive stripping voltammetry also enabled stability constant data to be obtained. Data for [BF4]– complexes with Sn2+ and Pb2+ thus obtained are in excellent agreement with those derived from the use of amalgam electrodes.

Liquid-liquid extraction of some m II and m III ions with 2-ethylhexylhydrogenphenylphosphonate

The extraction of zinc(II), cadmium(II), bismuth(III) and some lanthanide ions from aqueous perchloric acid into hexane solutions of 2-ethylhexylphenylphosphonic acid, HEHØP, has been studied. The extracted species contain varying numbers of extractant molecules and phosphonate groups as ligands, depending upon the size and charge of the ions. High loadings of the extractant with the metal ion resulted in suppression of the extraction. Alkali ions were not extracted but alkali perchlorate suppressed the extraction through the effect of ionic strength on the metal ion activity.

ChemInform Abstract: The Electrochemical Synthesis of O‐Ethylxanthato and N,N′‐Dimethyldithiocarbamato Complexes of Indium(III), Tin(IV), Lead(II), Bismuth(III) and Tellurium(IV).

AbstractThe one‐step electrochemical oxidation of the appropriate metal in the presence of an acetone solution of ethyl dixanthogen or tetramethylthiuram disulfide yields the title compounds (I)‐(IV).

The electrochemical synthesis of O-ethylxanthato and N,N′-dimethyldithiocarbamato complexes of indium(III), tin(IV), lead(II), bismuth(III) and tellurium(IV)

The O-ethylxanthato and N,N′-dimethyldithiocarbamato main group metal complexes were produced by the one-step electrochemical oxidation of the metal (M = In, Sn, Pb, Bi, Te) in the presence of an acetone solution of ethyl dixanthogen or tetramethylthiuram disulphide.

Potentiometric stripping analysis with a thin-film gold electrode for determination of copper, bismuth, antimony, and lead

The in situ thin-film gold electrode at glassy carbon substrate has been successfully used as a working electrode in potentiometric stripping analysis. Gold(III) present in the solution studied also serves as an oxidant. The equations for the transition time (stripping signal) and for the stripping curve of potentiometric stripping analysis have been derived and verified experimentally for copper(II), bismuth(III), antimony(III), and lead(II), in 0.1 M HCl. This method is available for the simultaneous determination of these four ions used for sample analysis.

Simultaneous Determination of Heavy Metals in Water by High Performance Liquid Chromatography after Solvent Extraction of Heavy Metals as Hexamethylenedithiocarbamato Chelates

Abstract A simple, rapid, precise and accurate method for the simultaneous determination of ppb levels of cadmium(II), nickel(II), cobalt(II), copper(II), bismuth(III) and mercury(II) in water was developed. The six heavy metals described above in 50 ml of water sample were quantitatively extracted into 1.0 ml of chloroform by shaking for 15 min as their hexamethylenedithiocarbamato chelates (HMDC chelates), then separated by reversed-phase high performance liquid chromatography (HPLC) and the eluted metal chelates were monitored at 260 nm. The six HMDC-metal chelates were successfully separated on a 5 μm ODS column (4.6 × 150 mm, Cosmosil 5 C18), using methyl alcohol-water-diethyl ether-buffer solution (NH4Cl-NH3, pH 7.5)-10−3M hexamethyleneammonium hexamethylenedithiocarbamate (HMA-HMDC)=82:9:3:3:3 as the eluent. The linear working curves for the six metals were obtained in the concentration range of 0.3–2000 ng/ml (ppb). Detection limits were 45–600 pg as metals. The recovery and the precision of the p...

Fluorophotometric determination of sulfide ion and 8-hydroxyquinoline with 3, 4, 5, 6-tetrachloro-fluorescein mercury compound.

An imporved method for the fluorophotometric determination of micro amounts of sulfide ion and 8-hydroxyquinoline were developed by using five halogenofluorescein mercury compounds as the reagents. The fluorescence intensities of silfide ionhalogenofluorescein mercury compounds and 8-hydroxyquinoline-halogenofluorescein mercury compounds were examined. Among them 3, 4, 5, 6-tetrachlorofluorescein mercury compound (T. Cl. Fl. Hg4) formeda very stable, pink colors with sulfide ion or 8-hydroxyquinoline in the presence of polyvinylpyrolidone, and a marked decrease in the fluorescence intensity of T. Cl. Fl. Hg4 solution accompanied with the color formation. Consequently, the fluorescence intensity of T. Cl. Fl. Hg4-sulfide ion or T. Cl. Fl. Hg4- 8-hydroxyquinoline complex was applied to a sensitive and simple fluorophotometric determination of minute amounts of sulfide ion and 8-hydroxyquinoline. Maximum difference of fluorescence intensity between T. Cl. Fl. Hg4 solution and T. Cl. Fl. Hg4-sulfide ion or T. Cl. Fl. Hg4-8-hydroxyquinoline solution was observed at 550nm, and the fluorescence intensities were constant in the pH range from 6.4 to 7.0 for determination of sulfide ion and from 8.8 to 9.5 for determination of 8-hydroxyquinoline by adjustment, respectively. The calibration curves were linear in the concentration range of 0 to 40μg/10ml for sulfide ion and 0 to 20μg/10ml for 8-hydroxyquinoline, respectively. The effects of diverse ions on the fluorophotometric determination of sulfide ion and 8-hydroxyquinoline were examined. Zinc (II), lead(II), bismuth(III) and copper(II) could be masked by addition of iminodiacetic acid or nitrilotriacetic acid soluiton, but thiocyanate ion, thiosulfate ions and ammonium ion must be avoided. The reaction is quite sensitive, and the procedure is simple.

Catalytic effect of copper on the hexacyanoferrate(III)—cyanide redox reaction—II catalytic determination of copper

A catalytic method for the determination of copper, based on the catalysis of the hexacyano-ferrate(III)—cyanide redox reaction, is proposed. Experimental conditions to achieve the lowest detection limit are selected from the kinetics of both the catalysed and the uncatalysed reactions. The experimental measurements can be made at room temperature without close control. The rate-constant method is the most sensitive and precise, whereas the fixed-concentration and fixed-time methods appear to be the most rapid for routine analysis. A detection limit of 1.3 ng/ml and a coefficient of variation of about 3% for the determination of 63 ng/ml can be achieved. The catalytic effect of copper seems to be highly specific. Lead(II), bismuth (III), antimony (III), iron (II), iron(III), chromium(III), lanthanum(III), cerium(III), titanium(IV), zirconium(IV) and uranium(VI) interfere by precipitation. Species such as tin(II), cobalt(II), manganese(II), sulphite and thiosulphite cause serious interference because they react with hexacyanoferrate(III). Chromate interferes by its colour. Suitable methods to avoid the interferences from antimony(III), iron(III), chromium(III), titanium(IV), zirconium(IV), uranium(VI) and chromate are proposed.

ChemInform Abstract: PRECISE MEASUREMENT OF IONIC DIFFUSION COEFFICIENTS WITH A HANGING MERCURY DROP ELECTRODE

AbstractDie Diffusionskoeffizienten von Tl+, Cd2+‐, Bi3+‐ und Co(NH3)63+‐Ionen in wäßrigen 0,1 Mol dm‐3‐KNO3‐Lösungen werden bei 25°C aus der Zeitabhängigkeit des diffusionsbestimmten Stromes an einer kugelförmigen Elektrode bekannter Größe bestimmt.